Muddy is right
Muddy Cup is right. In my shops I always left a section, if not the whole board( of the sidewalk A-frame), for the opener to "express" themselves in what ever manner they wanted(within reason)...cartoons, trite quotes, Haiku whatever.
Had lots of customers come by just to check out what we had to say that day and the employees loved it..stimulated lots of good conversations/arguments....but you have to get a whitty opener and it helped that my shops were located on or near a University that was more or less liberal or was not turned off by others opinions. Election years were always lots of fun round here especially since Bush was in Austin. One of the most memorable read: "Vote for Bush! Get him the Hell out of Austin". Sombody later ripped the quote and printed up bumper stickers. Go a bit of free press out of it too. Have fun with it.